Presentation
Abdominal pain.
Patient Data
Acute occlusive thrombus of the SMV extending along its whole length, partially extending to the portal and splenic veins with periportal collaterals. Associated mesenteric oedema.
Normal CT features of the different small and large intestinal loops, with no abnormal enhancement, mural thickening or peri-intestinal mesenteric lesions. No CT signs of related bowel wall congestion or ischaemia.
The liver is of normal size, and diminished tissue density (Mild fatty liver).
Case Discussion
The patient presented with abdominal pain and no characteristic certain differential and so, triphasic CT abdomen with entero-colonography preparation was done. The portal venous phase series (shown) shows occlusion of the superior mesenteric vein (SMV) with no signs of bowel ischaemia.
Acute superior mesenteric vein thrombosis is one of the less common causes of acute mesenteric ischaemia. Despite thrombosis of the SMV, small bowel necrosis is less likely to occur, presumably due to persistent arterial supply and some venous drainage via collaterals. Acute thrombosis may be difficult to detect in non-contrast studies or at the arterial phase as the thrombus may be iso- or hypodense and not usually hyperdense. The diagnosis is made on portal venous phase contrast-enhanced studies.